Evidence of Recent Intricate Adaptation in Human Populations.

Area of Science:

• Human evolutionary genomics
• Population genetics
• Molecular evolution

Background:

• Recent human adaptations have led to population differentiation in genomic regions with functional variants, often in regulatory elements.
• The precise functions of these variants and the mechanisms of recent adaptation are not fully understood.

Purpose of the Study:

• To investigate the functionality of gene and repeat regions based on population differentiation metrics (FST and ΔDAF).
• To explore the role of regulatory elements in recent human adaptation and population divergence.

Main Methods:

• Analysis of gene and repeat regions using FST and ΔDAF to assess population differentiation.
• Expression quantitative trait loci (eQTL) analyses in lymphoblastoid cell lines to identify regulatory variants.
• Examination of variant frequency distributions to infer selective pressures.

Main Results:

• High FST values in untranslated regions (UTRs) suggest regulatory differences drive population divergence.
• eQTL analyses confirm many population-specific regions are cis- and/or trans-eQTLs.
• East Asian and European populations show evidence of mutual selection, while African populations exhibit broader, slighter adaptation.
• RNF135 identified as a trans-regulation hotspot influenced by population-specific cis-regulation.

Conclusions:

• Human population differentiation is significantly shaped by regulatory element evolution and adaptation.
• Recent human adaptations involve complex regulatory mechanisms, with varying strengths across populations.
• The study provides evidence for intricate human adaptation driven by regulatory manipulation.